Field of the invention
The invention relates to a cutting insert having a substantially triangular or square basic shape with a top surface and a base surface which are connected to one another by lateral flanks, wherein three or respectively four cutting edges, which are convex as seen in plan view, are formed by the intersection between top surface and the flanks and/or between base surface and the flanks, which cutting edges each consist of at least a circular arc and at least one substantially straight section and are connected to one another via cutting corners having a corner radius Re.
Such a cutting insert is described in EP 1 689 548. Cutting inserts of this type are primarily used for face milling at high feed rates in the order of magnitude of 0.5 to 3 mm/tooth with small cutting depths up to at most 2 mm in order to machine flat faces as efficiently as possible.
In a preferred configuration of a cutting insert according to this citation, the radius of the circular arc is within a range which is greater than and at least twice as large as the radius of the inscribed circle. This specification restricts the possible angular configuration between main cutting edge and wiper edge for the design of the cutting insert to a relatively small range. In addition, the cutting insert has no encircling cutting edge chamfer, and therefore the strength of the cutting edges, in particular during the milling of steps and shoulders, is often not sufficiently robust.